Process for rolling rings



Febf19, 1935.

B. BELL Filed April 16, 19:52 2 sheets-sheet 1 ZQI@ l Feb. 19, 1935. FQ B. BELL 1,991,486

' PRocEss .Fon ROLLING- RINGS Filed April 16,l 1932 2 sl1ee1;s-'smaetl` z or flanged contours.

Patented Feb. 19, 1935 UNITED f STATES- PROCESS Foa ROLLING mNGs Frank B. Bell, Pittsburgh,` Pa., assigner to Edgewater Steel Company, Pittsburgh, Pa., a corporation oi' Pennsylvania Application AprillG, 1932, Serial No. 605,686

2 Claims.

This invention relates to the rolling of metal rings or bands and has for its object broadly the provision of an improved process for producing continuous metal rings or bands having irregular While the invention will be hereinafter more particularly described as embodied in a process for producing rings or bands adapted to form the cylindrical parts of brake drums which are provided with a multiplicity of radial anges for heat radiation, it will be readily apparent that the invention has other valuable application.

The `invention contemplates the rolling of a band of metal, such as steel, from a bloom by enlarging its diameter and reducing correspondingly its cross-sectional area to provide a smooth cylindrical inner face and a number of outwardly extending or radial circumferential flanges. Considerable difculty has been experienced in efforts to roll a ring or band of this character and particularly in the flowing of the metal into the anges upon the peripheryas the diameter is enlarged and the sectional area diminished; that is to say, the roll or rolls which define this outer surface are of necessity recessed to receive and define the flanges required, and in the rolling of the ring it has appeared impossible to provide sufiicient pressure to force the metal into these recesses as the diameter enlarges.

I have discovered that this may be overcome byrolling the flanges upon the bloom before substantial enlargement of its diameter and While the cross-sectional area is relatively large or deep radially of the bloom. Preferably also the formation of these flanges is attended by some reduction in the lateral width of the bloom so that this metal in being displaced tends ,to force outwardly the outer face ofthe bloom i'nto the flange producing recesses of the roll determining the circumferential face of the bloom and later the band.

In 'accordance with my of the bloom is preferably held substantially at constant diameter during the formation of the `iianges upon the'outer face and the edging or width determining rolls vare forced in concurrently with the pressure of the bloom against the face of the iianged or main roll. After the flanges videtheir increased circumferential dimensions.

same, certain of the rolls invention the diameterv (c1. zii-152.2)

`illustrates a preferred embodiment thereof.

Referring to the drawings: Figure 1 is aside elevation of an ingot section adapted to be employed to produce a ring or band 10 in accordance with my invention;

Figs. 2, 3,'4 and 5 are sectional views showing stepsV in the development of the finished ring in accordance with the practice of the process of this application; v

Fig. 6 is an enlarged fragmentary section taken through a side of a finished ring or band;

Fig. 7 is a plan View showing schematically an organization of rolls adapted for the practice of the process; 2

Fig. 8 is a transverse sectional view through the being shown in elevation and Fig. 9 is a view similar to Fig. 8 showing the position of the rolls at the end of the rolling 25 operation.

` Figs. 5 and 6 illustrate in section a ring or band' adapted to form the cylindrical member of an automobile brake drum. The inner surface 11 of this band.. generallyindicated by reference character 12, is of smooth accurate cylindrical form and is adapted to be engaged by the braking members to accomplish the braking action.

At one side the ring' 12 is providedy .with an outer cylindrical part 13 adapted for attachment 35 by spot welding or otherwise to the side or wedge member of the drum. The ring l2 is provided with a plurality of central circumferential outwardly extending anges 14 and an edge flange o 15 which are provided for radiation of the heat in braking.

In accordance with the invention the band 12 is formed i'romv a single ingot section, generally indicated by reference character 1'6. The ingot 45 section 16 is first flattened andpartially perforat ed at 17 as indicated in Fig. 2. The perforation is completed and the opening through the ring somewhat enlarged asindicated at 18 in-Flg. 3. The bloom thus provided is preferably somewhat thicker than the width desired in the nished ring or band 12 and my invention contemplatesthe rolling of the bloom of Fig. 3 into the finished ring with the'vradially-extending vanges 14 andv 15 by a sequence of steps which may be accom- 5 5 matically shown in Figs. 'I to 9.

Referring to Figs. 'I to 9, reference character .'21 indicates a main roll provided with alternately arranged flanges 22 and depressions 23 together having contour matingvwith the contour of the ring, as indicated in Figs. 5 to 9.

'I'he main roll 21 is or may be fixed in position and isl adapted for co-operation with a-follower roll 24 which is arranged within the bloom and which is movable'toward the axis of the roll 21 to force the metal of the bloom against .the pressure roll. Two edging rolls, indicated respectively by reference characters 25 and 26, are provided to determinethe width of the ring and to engage and diminish the thickness of the bloom. These rolls are movable toward and from each other and together are movable toward and from the axis of the roll 21. Four guide and conned rolls 27 are provided as may be observd in Fig. 7.

In accordance with the invention, the bloom is positioned over the follower roll 24 and pressure is exerted both by the edging rolls 25 and 26 and by the guide rolls to force the outer face stantial enlargement of diameter and the rolls.

25 and 26 are caused to approach 'each other to somewhat diminish the thickness of the bloom.

After the rolling has proceeded without substantial enlargement of the diameter of the bloom sufllciently to fill the recesses 23 of the main roll 21, the diameter is enlarged, the edging rolls maintaining or substantially maintaining the width of the ring as the enlargement progresses.-

It has been discovered that after the initial formation of the flanges 14 and 15' bythe main roll and while the bloom is of small diameter,Y

the foregoing description and it will be apparent that various changes may be made in the and their order of accomplishment of theprocess described without departing from the spirit andscope of the invention or sacrificing all of its material advantages. the process hereinbefore described being merely a preferred embodiment thereof. A

, 1. The process of .fabricating blanks for-brake drums and the like having a uniformly dense molecular structure circumferentially, which comprises compressinga circular section of a bar of steel axially to form a disk and simultaneously partially perforating-the same, completing the perforation and enlarging the-same by spread' v ving the metal radially to. form an'annulua and enlarging and shaping the annulus to final form A by flowing the metal circumferentially while maintaining the axial dimension thereof substantially constant, thus producing substantially uniform stresses throughou/t the sectional area of the annulus and compressing the same to obtain a relatively dense molecular arrangement adapted to resist strains exerted on a brake drum fabricated from said annulus.

2. The process of fabricating brake drums and the like having a uniformly dense molecular structure circumferentially, which comprises compressing a circular section -of a bar of steelf axially tol form a disk, partially perforating the 3o same and simultaneously completing the perforation and enlarging the same by spreadingv the metal radially to form an annulus, rolling the internal and external circumferential surfaces of the annulus to provide a at inner surface and a Aflanged outer surface, simultaneously rolling the opposed lateral surfaces of the annulusl at apoint circumferentially spaced from a point where th'e circumferential surfaces of the annulus are rolled, and thereafter reducing the thickness of 'the annulus radially and increasing the diameter thereof while maintaining the width and outer circumferential connguration of said annulus constant thus insuring substantially uniform stresses throughout the sectional area of the annulus, and obtaining a relatively dense molecular arrangement adapted to resist strains exerted on a brake drum fabricated fromf said annulus. i,

FRANKB. BELL.- 

